1. Field of the Invention
The present invention relates to an electrical safety device. More particularly, the invention relates to a temperature sensitive and controlled circuit breaking device that is arranged to electrically disconnect a load from a power source with the occurrence of an over-temperature event associated with the delivery of power from the power source to the load.
2. Background and Objects of the Invention
The cross-referenced patents listed above to Kopelman disclose safety devices that will monitor the current flowing through a hot or supply conductor, essentially via a sensed temperature (associated with the current flow). The devices are configured with a temperature sensitive relay (and or over-current sensitive device) that is operable between a closed position or closed state when the relay is sufficiently cool, and an open position or open state when the temperature of the relay, or equivalently packaging the relay is housed in, is above a predetermined limit temperature. An over-temperature event of these devices may require manual resetting to again enable power to be coupled to a load, or alternately, may reset automatically by sufficient radiational cooling (over a sufficient temporal period). Each of the cross referenced patents, as listed above, is hereby incorporated herein by reference.
However, in the preferred embodiments of the above discussed inventions, the temperature controlled relay may only be electrically and or mechanically coupled to a `hot` or power sourcing conductor. Accordingly, there is a possibility that heat generated by other conductors (or related structures and current carrying means) may not be appropriately sensed due to their physical location and possibly due to the nature of the electrical connections of the temperature controlled relay. It is important to understand that when referring to the sensing of heat produced by the flow of current (possibly due to an excessive `over-current`), such sensing may be realized in several possible ways. Namely, either by indirect thermal conduction through convection or heat flow through a non-current carrying thermal conductor (say via a suitable thermal conduction means, such as air or an appropriate potting material) or through a direct coupling (say via the thermal conduction along an electrical conductor or one or more metal parts such as a plug prong).
Therefore, when considering prior art circuit interrupters, there is currently lacking a simple and cost effective arrangement to thermally sense and monitor the heat produced by any of a plurality of current carrying means (e.g., wires, conductors, etc.) to determine if the temperature of any one of said means has risen above a predetermined limit. For example, an elevated temperature level may be caused by a poorly formed resistive contact and or an excessive current flow of a neutral conductor or even a ground conductor.
Objects of the present invention are, therefore, to provide new and improved temperature controlled circuit interrupters having one or more of the following capabilities, features, characteristics, or advantages:
arranged to effect the coupling of a load to a suitable power source, or alternately, to disconnect the load from the power source should an `over-temperature` (and or over-current) event associated with the delivery of power from the power source to the load occur; PA1 employs at least one temperature controlled relay, possibly employing temperature sensitive `bi-metal` heat (and or current) responsive contact means; PA1 configurable as self or automatic resetting interrupters, or alternately, may be arranged to require manual resetting; PA1 resetting of the interrupter may be effected by disconnecting the power source for a sufficient temporal period to effect suitable cooling of the temperature controlled relay, thereby causing the resetting of the circuit interrupter; PA1 may employ a position and proximity arrangement to enable the temperature controlled relay (via air and convection) to be thermally coupled to a portion of each of a plurality of the current carrying conductors (and or other current carrying means) to sense an over-temperature event (due to the heating of any of a number of the current carrying means); PA1 may employ a volume of a thermally conductive potting material, or a functional equivalent, to thermally couple at least a portion of each of a plurality of the current carrying conductors (and or other current carrying means) to the temperature controlled relay for sensing thereby; PA1 may be employed with 2 pole/single phase power sources or multi-pole/multi-phase power sources; PA1 configurable as self-contained, compact, in-line devices, such as plugs, (duplex) outlet sockets, switches, dimmers, multi-outlet power strips, cords, etc.; and PA1 simple low cost embodiments using many off-the shelf components.
The above listed objects, advantages, and associated novel features of the present invention, as well as others, will become more apparent with a careful review of the description and figures provided herein. Attention is called to the fact, however, that the drawings and the associated description are illustrative and exemplary only, and variations are certainly possible.